将php数组转换为逗号分隔的字符串列表

Question

I have the following array:

$arr = [
    0 => 'value1',
    1 => 'value2',
    2 => 'value3'
];

The select function of my db class takes arguments in the following format:

DB::table('users')->select('value1', 'value2', 'value3')

How can I convert my array to pass those values in my select function?

I tried implode(',', $arr) and it gives one string with comma separated values, but what I want is not a single string, it's a list of comma separated strings like in the example above.

Thanks for any help.

Answer 1

select() can accept an array, so try:

DB::table('users')->select($arr);

This is source code of select() method :

public function select($select = null)
{
    ....

    // In this line Laravel checks if $select is an array. If not, it creates an array from arguments.
    $selects = is_array($select) ? $select : func_get_args();

Answer 2

You can do this in Laravel 5.8 as follows:

DB::table('users')->select('username')->pluck('username')->unique()->flatten();

Hope this helps.